Get access to generator modifier x values for drivers
Looks like you cannot access this property, but there is a workaround by scripting the generator yourself and by adding 2 custom ID properties to the object to control it.



import bpy

class Panel(bpy.types.Panel):
    bl_label = "Custom Panel"
    bl_space_type = 'VIEW_3D'
    bl_region_type = 'TOOLS'

    def draw(self, context):
        layout = self.layout
        layout.prop(context.active_object, '["offset"]')
        layout.prop(context.active_object, '["multiplier"]')

def register():
    bpy.utils.register_module(__name__)

def unregister():
    bpy.utils.unregister_module(__name__)

if __name__ == "__main__":
    register()